An application programming interface (API) is a specification intended to be used as an interface by software components to communicate with each other. Currently it is very difficult to sell and distribute APIs on the Internet or on any other networks. An API creator has to develop the backend, such as create and populate a database and implement function calls to other APIs, in order to expose the API. Furthermore, if the API creator wants to sell the API, then the API has to be integrated with complicated distribution and billing systems that typically require expert knowledge to use.